Next-Gen Catalyst Enables Energy-Efficient Carbon Dioxide Conversion

Carbon dioxide (CO_₂) is a major greenhouse gas, but it can also be used as a raw material to create useful products such as methanol, an important fuel and building block for many chemicals.

Conventional CO_₂ hydrogenation—a chemical process in which carbon dioxide reacts with hydrogen gas to produce chemicals or fuels—typically requires relatively high temperatures above 250 degrees Celsius, which increases energy demand and limits efficiency. 

Chemical and Biomolecular Engineering Professor Rachel Getman and S.M. Gulam Rabbani, a postdoctoral researcher, are part of a team of researchers who designed a new catalyst that converts carbon dioxide and hydrogen into methanol efficiently at much lower temperatures than conventional industrial catalysts. Their paper, “Isolated and H2-reduced Anderson clusters catalyze low-temperature hydrogenation of CO_₂ to methanol,” was published in Nature Chemistry. 

The team’s long-term goal is to transform carbon dioxide from a waste product into a useful raw material for chemical manufacturing.

“Our catalyst operates effectively at substantially lower temperatures and achieved methanol yields that exceeded those of many state-of-the-art catalysts under comparable low-temperature conditions,” Getman said. “If the design principles uncovered in this work can be translated into practical industrial systems, they could help reduce the energy required for carbon utilization processes and contribute to more sustainable chemical manufacturing.”

For over a decade, Getman and her research group have been studying how atomically precise metal-oxide clusters can be incorporated into porous materials called metal-organic frameworks (MOFs) to create highly defined catalytic sites. 

“A major challenge in catalysis is that conventional catalysts often contain many different types of active sites, making it difficult to determine exactly how reactions occur,” she explained. “Previously, we worked with collaborators to understand the structure and function of well-defined catalyst clusters within MOFs. In this study, we build on that foundation by showing that a single platinum-containing cluster confined within a MOF can catalyze carbon dioxide hydrogenation to methanol with exceptional activity, stability and selectivity.”

The researchers have demonstrated the catalyst in a laboratory-scale continuous flow reactor and shown that it can operate for more than 3,600 hours without measurable loss of activity or methanol selectivity.

“That is highly unusual for this type of reaction,” Getman said.

The team’s next challenge is determining whether the design can become an economically viable industrial technology. One important consideration is that the catalyst contains platinum—a scarce, expensive metal. Future work could focus on quantifying catalyst productivity over its entire lifetime and, if needed, reducing the amount of precious metal required. 

Despite the challenges, Getman is excited about the research’s potential impact.

“One particularly exciting aspect of this work is that it combines experiment and computation in a highly integrated way,” she said. “Because the catalyst contains a precisely defined atomic structure, we were able to use advanced spectroscopy together with molecular simulations to determine not only that the catalyst works, but also how it works. This level of mechanistic understanding is rare in heterogeneous catalysis and creates significant insights for catalyst design.” 

Additional study co-authors are Qin Liu, Haofan Yang and Joseph T. Hupp at Northwestern University; Zhenhao Hou and Wentuan Bi at the Institute of Energy, Hefei Comprehensive National Science Center; and Zhihengyu Chen and Karena W. Chapman at Stony Brook University.